/*
   * linux/drivers/cpufreq/freq_table.c
   *
   * Copyright (C) 2002 - 2003 Dominik Brodowski

   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   *

   */
  
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/cpufreq.h>

  /*********************************************************************
   *                     FREQUENCY TABLE HELPERS                       *
   *********************************************************************/
  
  int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
  				    struct cpufreq_frequency_table *table)
  {
  	unsigned int min_freq = ~0;
  	unsigned int max_freq = 0;

  	unsigned int i;

  	for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {

  		unsigned int freq = table[i].frequency;
  		if (freq == CPUFREQ_ENTRY_INVALID) {

  			pr_debug("table entry %u is invalid, skipping
  ", i);

  
  			continue;
  		}

  		pr_debug("table entry %u: %u kHz, %u index
  ",

  					i, freq, table[i].index);

  		if (freq < min_freq)
  			min_freq = freq;
  		if (freq > max_freq)
  			max_freq = freq;
  	}
  
  	policy->min = policy->cpuinfo.min_freq = min_freq;
  	policy->max = policy->cpuinfo.max_freq = max_freq;
  
  	if (policy->min == ~0)
  		return -EINVAL;
  	else
  		return 0;
  }
  EXPORT_SYMBOL_GPL(cpufreq_frequency_table_cpuinfo);
  
  
  int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
  				   struct cpufreq_frequency_table *table)
  {
  	unsigned int next_larger = ~0;

  	unsigned int i;

  	unsigned int count = 0;

  	pr_debug("request for verification of policy (%u - %u kHz) for cpu %u
  ",

  					policy->min, policy->max, policy->cpu);

  
  	if (!cpu_online(policy->cpu))
  		return -EINVAL;

  	cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
  				     policy->cpuinfo.max_freq);

  	for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {

  		unsigned int freq = table[i].frequency;
  		if (freq == CPUFREQ_ENTRY_INVALID)
  			continue;
  		if ((freq >= policy->min) && (freq <= policy->max))
  			count++;
  		else if ((next_larger > freq) && (freq > policy->max))
  			next_larger = freq;
  	}
  
  	if (!count)
  		policy->max = next_larger;

  	cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
  				     policy->cpuinfo.max_freq);

  	pr_debug("verification lead to (%u - %u kHz) for cpu %u
  ",

  				policy->min, policy->max, policy->cpu);

  
  	return 0;
  }
  EXPORT_SYMBOL_GPL(cpufreq_frequency_table_verify);
  
  
  int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
  				   struct cpufreq_frequency_table *table,
  				   unsigned int target_freq,
  				   unsigned int relation,
  				   unsigned int *index)
  {

  	struct cpufreq_frequency_table optimal = {
  		.index = ~0,
  		.frequency = 0,
  	};
  	struct cpufreq_frequency_table suboptimal = {
  		.index = ~0,
  		.frequency = 0,
  	};

  	unsigned int i;

  	pr_debug("request for target %u kHz (relation: %u) for cpu %u
  ",

  					target_freq, relation, policy->cpu);

  
  	switch (relation) {
  	case CPUFREQ_RELATION_H:

  		suboptimal.frequency = ~0;
  		break;
  	case CPUFREQ_RELATION_L:
  		optimal.frequency = ~0;

  		break;
  	}
  
  	if (!cpu_online(policy->cpu))
  		return -EINVAL;

  	for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {

  		unsigned int freq = table[i].frequency;
  		if (freq == CPUFREQ_ENTRY_INVALID)
  			continue;
  		if ((freq < policy->min) || (freq > policy->max))
  			continue;

  		switch (relation) {

  		case CPUFREQ_RELATION_H:
  			if (freq <= target_freq) {
  				if (freq >= optimal.frequency) {
  					optimal.frequency = freq;
  					optimal.index = i;
  				}
  			} else {
  				if (freq <= suboptimal.frequency) {
  					suboptimal.frequency = freq;
  					suboptimal.index = i;
  				}
  			}
  			break;
  		case CPUFREQ_RELATION_L:
  			if (freq >= target_freq) {
  				if (freq <= optimal.frequency) {
  					optimal.frequency = freq;
  					optimal.index = i;
  				}
  			} else {
  				if (freq >= suboptimal.frequency) {
  					suboptimal.frequency = freq;
  					suboptimal.index = i;
  				}
  			}
  			break;
  		}
  	}
  	if (optimal.index > i) {
  		if (suboptimal.index > i)
  			return -EINVAL;
  		*index = suboptimal.index;
  	} else
  		*index = optimal.index;

  	pr_debug("target is %u (%u kHz, %u)
  ", *index, table[*index].frequency,

  		table[*index].index);
  
  	return 0;
  }
  EXPORT_SYMBOL_GPL(cpufreq_frequency_table_target);

  static DEFINE_PER_CPU(struct cpufreq_frequency_table *, cpufreq_show_table);

  /**

   * show_available_freqs - show available frequencies for the specified CPU

   */

  static ssize_t show_available_freqs(struct cpufreq_policy *policy, char *buf)

  {
  	unsigned int i = 0;
  	unsigned int cpu = policy->cpu;
  	ssize_t count = 0;
  	struct cpufreq_frequency_table *table;

  	if (!per_cpu(cpufreq_show_table, cpu))

  		return -ENODEV;

  	table = per_cpu(cpufreq_show_table, cpu);

  	for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {

  		if (table[i].frequency == CPUFREQ_ENTRY_INVALID)
  			continue;
  		count += sprintf(&buf[count], "%d ", table[i].frequency);
  	}
  	count += sprintf(&buf[count], "
  ");
  
  	return count;
  
  }
  
  struct freq_attr cpufreq_freq_attr_scaling_available_freqs = {

  	.attr = { .name = "scaling_available_frequencies",
  		  .mode = 0444,

  		},

  	.show = show_available_freqs,
  };
  EXPORT_SYMBOL_GPL(cpufreq_freq_attr_scaling_available_freqs);
  
  /*
   * if you use these, you must assure that the frequency table is valid
   * all the time between get_attr and put_attr!
   */

  void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,

  				      unsigned int cpu)
  {

  	pr_debug("setting show_table for cpu %u to %p
  ", cpu, table);

  	per_cpu(cpufreq_show_table, cpu) = table;

  }
  EXPORT_SYMBOL_GPL(cpufreq_frequency_table_get_attr);
  
  void cpufreq_frequency_table_put_attr(unsigned int cpu)
  {

  	pr_debug("clearing show_table for cpu %u
  ", cpu);

  	per_cpu(cpufreq_show_table, cpu) = NULL;

  }
  EXPORT_SYMBOL_GPL(cpufreq_frequency_table_put_attr);
  
  struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu)
  {

  	return per_cpu(cpufreq_show_table, cpu);

  }
  EXPORT_SYMBOL_GPL(cpufreq_frequency_get_table);

  MODULE_AUTHOR("Dominik Brodowski <linux@brodo.de>");
  MODULE_DESCRIPTION("CPUfreq frequency table helpers");
  MODULE_LICENSE("GPL");